The present application relates to a semiconductor structure and a method of forming the same. More particularly, the present application relates to an electrical fuse (e-Fuse) that has a thin fuse link that is located laterally between, and in contact with, an anode and a cathode.
In addition to transistors, resistors, capacitors, and diodes, semiconductor devices also often contain fuses. These fuses may be used for several purposes. For example, fuses may be used within semiconductor devices for purposes of introducing or deleting customized circuit elements into a semiconductor device. In addition, fuses within semiconductor devices may be used for purposes of severing a non-operative portion of the semiconductor device and replacing that non-operative portion with a redundant semiconductor device fabricated on the same semiconductor substrate. Fuse elements may also be used to provide direct alternative current (DAC) trimming.
Selected fuses are usually blown by either a laser beam, or an electrical current, depending on the design of the fuse/device. In an electrical fuse design, electronically programmable fuses are blown by passing a current through the fuse link. The electrical current then causes a permanent change to the resistance of the fuse. The fuses that are blown are selected by one or more programming methods, which are generally known to those skilled in the art. Electronically programmable fuses, also called e-Fuses, have become popular because of the circuit and systems design flexibility that they provide.
e-Fuses are used in semiconductor industry to implement array redundancy, field programmable arrays, analog component trimming circuits and even as chip identification circuits. Dog-bone shaped e-Fuses containing a fuse link are known. In such conventional dog-bone shaped e-Fuses, the fuse link dimension is limited by the allowable photolithographic minimal dimensions.
While e-Fuses are thus desirable within semiconductor device design and fabrication and provide an essential tool for cost effective and efficient semiconductor device design and fabrication, e-Fuses are not entirely without problems. For example, programming of prior art e-Fuses typically takes a substantial amount of current, which is undesirable in current technology node devices using low driving current. In addition, programming transistors takes up space in a semiconductor chip as well as power consumption. In view of the above, there is a continued need to provide e-Fuses in which the fuse link is much smaller than conventional photolithographic minimum dimensions and thus the amount of electrical current that is needed to blow the e-Fuse can be substantially reduced as compared to a conventional e-Fuse design.